Surfacing machine



'Jmzs, 1941. RFrKNHsLE'Y f 2,229,745,

SURFAC IN G MACHI Filed July 10, 1940 2 Shets-Sheeg 1 -Rlchard E neislegJan. 28, 1941. R. F. KNEISLEY 2,229,745

SURFACING MACHINE Filed July 10, 1940 2 Sheets-i-Shet 2 jwvcnfon RlchardF. Knei'sley' mum Patented Jan. 28, 1941 UNITED STATES PATENT OFFICE2,229,745 SURFACING MACHINE Application July 10, 1940, Serial No.344,810 2 3 Claims.

This invention relates to surfacing machines, and particularly to smallportable machines of this character adapted to be hand operated andemployingrotary sanding disks.

The primary object of the invention is the provision of an improvedrotary disk type of machine of this character which is small and compactto enable it to be easily held and operated by either one or two hands,thus admirably adapting it for the sanding of boats, building walls andother objects where hand operation is required, and which has few partsand these compactly arranged and easily accessible, thereby renderingthe machine light in weight and enabling it to be easily and quicklyrepaired.

The invention is full described in the following specification, and oneembodiment thereof illus trated in the accompanying drawings, in whichFigure 1 is a side elevation of a machine embodying the invention; Figs.2 and 3 are sections of portions thereof, respectively, on the lines 2-2and 3-3 in Fig. v1; Fig. 4 is an enlarged fragmentary detail showing themanner in which the sanding disk is applied to the work and the flexingof the working edge thereof when in use; Fig. 5 is an enlarged centralvertical section of the machine with parts broken away, and Fig. 6 is aside elevation of the gear unit removed from the machine, with partsbroken away and with the abrading disk removed therefrom.

Referring to the drawings, l designates a hollow casing of smallelongated form with its top and sides preferably curved or of invertedU- form in cross-section to adapt it tov be conveniently held in onehand during handling. The casing is divided lengthwise by a partition 2into a gear compartment 3 and a motor compartment 4, the latter havingan open outer end which is closed by an end cap 5, secured to the casingat each side thereof by an end screw 6. The gear compartment 3 is formedwith a bottom 1 preferably inset slightly relative to the lower edge ofthe casing and having a large opening 8 substantially centrally disposedand closed by a plate 9. This plate is fitted into the opening, isflanged over the outer marginal edge wall thereof, and is securedthereto by screws Ill. The bottom of the motor compartment is closed, asshown at [2, in substantially the plane of the lower edge of the casing.

The motor armature I4 is disposed in the compartment 4 lengthwise of thecasing and has its shaft l5 journaled at one end in the cap 5 in asuitable bearing l6 and at its other end in the partition 2 in asuitable bearing H. The commutator brushes 20, two innumber, aredisposed in diametrically opposed relation, one at the top and one atthe bottom of the cap 5, and are mounted in respective openings 2| inthe cap. Each of the brush mountings,.in the present instance, includesan insulating bushing 22 fixedly mounted in the opening by a screw 23, abrush holding sleeve 24 slidingly mounted in the bushing for movementsradial to the commutator and through the inner end of which the brushprojects, and a screw 25 threaded from theouter end of the opening 2!into thasleeve 24 with its head shouldered against the bushing 22, sothat a turning of the screw will effect adjustment of the sleeve in thebushing. 'A coiled compression spring 26 is disposed between the screw25 and brush 20 to yieldingly hold the brush in engage- .ment with thecommutator.

The mounting means for the lower brush is disposed in. inwardly setrelation to the bottom I! of the casing I and access to the. screw 25thereof is had through an opening 21 in said bottom. This latteropeningis closed by a bushing 30 held in the opening by a set screw 3|,and into this bushing is screwed a sleeve 32 in which a snap switch ofany suitable form for the motor circuit is disposed. This -switch iscontrolled by a rotary button 33 which is ex,- posed at the under sideof the casing I, or, in the" present instance, at the'un'der side of thecap 5. The electric lead wires 35 enter the casing through an opening inthe upper portion of the cap 5, as shown, one being connected to theupper brush sleeve 24 while the other is con-f nected to the lower brushsleeve through'the switchand interposed motor field coil 36, whichlatter is mounted in the lower portion of the 2 motor compartment 4. Theswitch button is protected by an extension 31 on the loweredge of thecap 5 and is of circular form in crosssection to extend-partially aroundthe switch button 33 and is of a length1to extend below such button andserve as a-supporting foot for the rear end portion of the motor casing.

A ventilating fan 38 for the motor is mounted on the shaft iii in theforward part of the compartment 4, and circulation of air-is eii'ectedthrough said compartment and casing and cap openings 39.

The plate 9 which closes the bottom opening 8 of the gear compartmenthas a vertically oilset shelf portion supported from the plate by a webor leg portion 4| disposed in offset relation to the centers of theplate and shelf. A spindle 42 is mounted for rotation in suitablebearings 43 in said plate and shelf, the spindle being supported in thebearings by a nut 44 at and shelf, is journaled a short shaft 1. This,

shaft flxedly carries a pinion ll between the plate and shelf and indriving mesh with a gear I! fixed to the spindle 42 also between theplate and shelf. This pinion and gear are preferably but not necessarilyof spiral form. The shaft 41 at its upper end flxedly carriu a bevelgear llv in mesh with a bevel drive" pinion II on the projecting forwardend portion of the armature shaft I5. It is thus apparent that thespindle 42 is driven at a considerably reduced speed from the armatureshaft II through said shaft and gearing. It is also ap arent that the;spindle l2, shaft 41 and connected gearin'g, withthe exception of thedrive pinion II, are carried by the plate I and shelf ll as a unit, sothat it may be removed as an entirety from the casing to facilitateinspection and repairdor replacement of parts. g

The'abrading disk 80 comprises a metal hub portion I having an annularflange 82 near its upper end and having a'center opening through whichthe screw 45 is projected." The upper end of the hub is adapted to fitcentrally around the lower end of the spindle 42, while its lower end iscountersunk in' conical form to receive a conical clamping head 63carried by the screw II. The disk has a rubber body portion 64 which isvulcanized to the metal hub OI so that it forms an integral connectiontherewith. The rubber body 84 projects a distance radially of the hub toform a flexible annular flange portion, being flat at itsunder sideandhaving the top of its projecting flange portion tapering to graduallynarrow the depth of such portion to a comparatively thin edge where itmeets with the bottom surface. To facilitate flexing of the extendedportion of said body, along substantiallya straight radial line, thebody is weakened adjacent to its point of connection with the hub flange62 by the provision of an annular recess 65 in its top' surface. Theprovision of this recess provides the disk body with an annular toeportion which when pressed against the work with the diameter of thedisk at an incline to the work surface permits a flexing of such toeportion in substantially a straight line at its under side, asillustrated in Fig. 4, and causes the pressure of the flexed toe portionagainst the work to be substantially uniform throughout the radial depthof the toe portion. This is found to be important and desirable in theuse of machines of this character. The under side of the disk 60 isfaced with a sanding disk 66 which is preferably slightly larger indiameter thanthe disk body' 64 and has its central portion pressed upinto the conical body socket of the hub fil and clamped thereto by theclamping head 83 on the screw 45. I

To facilitate handling, the casing l is preferably provided on its.top'with a handle to be grasped by one hand and a knob II to be graspedby the other hand of the operator. In the present instance, the handleI0 is secured at its forward end by a screw 12 to a screw plug I! whichis threaded into a grease filling opening in the top of the casing.

It is apparent that I have provided a simple and compact surfacingmachine of the hand operated type; that the operating parts thereof maybe easily and quickly assembled in the casing, and connected foroperation, and that the parts are easily accessible for inspection,repair or replacement.

I wish it understood that myinvention is not limited to any specificconstruction or arrangement or form of the parts, as it is capable ofnumerous modifications and changes without departing from the spirit ofthe claims.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent, is:

1. In a machine of the class described, a hollow elongated casing havinga cross partition dividing the interior of the casing into a rear motorcompartment and a forward gear compartment, the bottom of the forwardcompartment having a removable part, a motor mounted in said rearcompartment with its armature shaft disposed lengthwise of the casingand mounted at its forward end in said partition and at its rear end inthe rear wall of the casing, an abrad ing disk carrying spindlejournaled vertically in said removable part and extending into thegearing compartment, a drive gear on the forward end of said motor shaftwithin the gear compartment, and speed reducing gearing carried by saidremovable part and providing a driving connection between said gear andspindle when the removable part is mounted in the casing. said gearingand spindle being carried by and removable as a unit from the casingwith said removable part.

2. In a machine of the class described, a hollow elongated casing havinga cross partition dividing the interior thereof into a rear motorcompartment and aforward gear compartment, said forward compartmenthaving an opening in its bottom, a motor mounted in said rearcompartment and having its armature shaft journaled at one end in saidpartition and projected forwardly therethrough, a drive gear on theforward end of said shaft, a plate 'removably closing said bottomopening, an abrading disk carrying spindle and a shaft carried by saidplate in spaced paralled relation and projecting into said forwardcompartment, said spindle being projected outwardly through the plate,and gearing carried by said last mentioned shaft and spindle andproviding a. driving connection between said drive gear and spindle,said spindle, shaft and gearing being carried by and removable as a unitfrom the compartment with said plate.

3. In a machine of the class described, a hollow elongated casing havinga cross partition dividing the interior of the casing into a rear motorcompartment and a forward gearing compartment, said motor compartmentbeing open one disposed inwardly with respect to the outer end of itsopening, a, rotatable snap switch for the motor removably mounted in theouter end of said lower opening with its control knob exposed below thebottom of the cap, said cap having a guard flange for the switch knobprojecting downwardly from its lower edge at the rear of said knob, anabrading disk carrying spindle projectlng through and journaled in thebottom of said forward compartment and projecting up into thecompartment, and speed reduction means connecting the forward end of 5said shaft to said spindle.

RICHARD F. KNEISLEY.

